Hand sander



April 8, 1952 c, w, w z 2,592,093

HAND SANDER Filed May 4, 1950 y i 1 X0 /7 /f g g INVENTOR. CHARLES W. WERNTZ AUM/Vf/ -ing.

Patented Apr. 8, 1952 Charles W. Werntz, Warrenton, Mo.

Application May 4, 1950, Serial No. 159,943

1 This invention relates generally to the art of finishing surfaces, such as by polishing or abradvMore specifically it is directed toward hand sanders and represents an improvement over the 1 universally employed expedient of a sandpaper facing and block. I

Sandpaper is secured to a rigid plate taking the form of a disk. However, the disk itself may be fashioned with an abrasive face. To the disk so equipped, a pintle is secured at its center. The pintle projects into a bore of a boss positioned to one side of a handle and is free to rotate therein. With this construction in mind it will 'be apparent that, when a workman applies a thrust to the handle such thrust will be directed essentially toward the center of the handle. Further, since the handle is afiixed to the central pintle on the side of the handle, the median of the thrust will be transmitted substantially away from the center of the disk. Also, since the thrust applied is not only forward and rearward in relation to the user, but is, in addition, directed against the work, a resultant increased drag or resistance is created on that portion to the disk underlying the handle. This disproportionate resistance on one side of the disk as compared to the other causes the disk to revolve on its axis in one direction when forced forward and reverse itself when forced to return rearward. Thus, the sandpaper, or abrasive facing of the disk, is worn evenly and not in a particular spot, as it is in the conventional use of a sanding block.

With the foregoing and other ends in view, the invention relates to certain new and useful constructions, combinations and arrangement of parts clearly described in the following specification and fully illustrated in the drawings, in which:

Fig. 1 is a plan view showing details of construction with hidden parts in dotted lines; and

Fig. 2 is a side elevational view shown in section as viewed along line 2-2 of Fig. 1.

Referring to the drawings embodying my invention, a disk It! has a pintle I I positioned thereon at its center. The pintle I I is adapted to carry a handle I2 in which the pintle H is free to revolve. The disk I carries on its underface a sandpaper facing I3 united to the disk ID by any suitable means such as cement I4 represented in Fig. 2. t may be here observed that suitable sandpaper, provided with cement for its ready adhesion to flat smooth surfaces such the disk I 8, is at present manufactured and sold commer- 3 Claims. (Cl. 51-186) cially. However, if it is so desired, the disk ID may be fashioned as to result in itsunderside being used directly as the abrasive agent. Or, other specific means may be used for attaching the abrasive to the face of the disk It].

The pintle II, being located on the disk- II) at its center, may be integrally formed. However, separate elements rigidly attached will, in most instances, prove to be satisfactory. The pintle .II, projecting from one side of the disk It, is

generally cylindrical in shape and has a circumferential groove 55 near its outer end I6. Carried by the groove I5 is an annular compressible spring I! normally of an expanded diameter greater than that of the pintle I I.

Proceeding further, the handle I2 formed of shell construction has contained therein on one side a boss I8 with a bore I9. The bore I9 is of a diameter large enough to receive the pintle I I and allow the latter to freely rotate therein. Since it is desirable that the handle I2 be secured in position so as to be permanently associated with the pintle II and disk I0, the spring I'I,

carried in the groove I", is provided to grip the wall of the bore I9. The spring H has an inside diameter sufficiently large to allow free rotation of the pintle II when it is compressed and has a compressed outside diameter slightly greater than that of the pintle I I which results in its tight frictional engagement with the walls of the bore I9.

The handle I2, in order to conform to the requirement of a hand, has located at its side a recess 20 adapted to receive the fingers of a hand. Further, a surface 2| on the handle I2 comfortably conforms to the palm of the hand and readily receives a thrust therefrom. Thus, the recess 20 and the surface 2| accommodate the hand and are used in conjunction.

Preferably, the handle I2 is cast of metal, such as aluminum or its alloy. It consists of a shell, with a boss I8, the shell having an upper surface 2 I, as described, to receive a thrust from the palm of a hand, and a groove 20 in a side to receive the ,tips of the fingers of the hand. The contour of abrasive face of the disk Iil in engagement with a surface to be sanded, while the handle is grasped in the hand and pushed forward and backward. Since the median or resultant of the thrust lies to one side of the pivot point, or center, of the disk, the disk in operation, as the device is pushed or pulled, is caused to rotate. Thereby the disk wears uniformly over its entire surface and not in a particular spot, as in the case when a piece of sandpaper is used with a simple block backing.

Various changes, within the scope of the appended claims, may be made without departing from the spirit of this invention; parts of the invention may be used without the whole; and improvements may be added while retaining the benefits of this invention.v

I claim:

1. A hand sander including a disk having an abrasive face; a pintle secured to the disk having an annular compressible spring carried in a groove on the upper end of the pintle; and a handle adapted to fit in the palm of a hand and receive a thrust therefrom, with a boss on one side bored to receive the pintle and retained on the pintle by means of the compressible spring bearing against the sides of the bore; the handle being connected with the disk at a point substantially to one side of the handle, whereby the median of the thrust is applied to the disk substantially to one side of its center, thereby'causing the disk to rotate with respect to the handle when the disk is pushed along a surface to be abraded.

2. A hand sander including a disk having an abrasive face; a pintle secured to the disk having 3 presenting a surface convenient to the palm of a hand, and having a groove on one side adapted to accommodate the fingers of the hand whereby the handle may receive a thrust from the hand; a boss on one side of the handle bored to receive the pintle and retaining the pintle by means of the compressible spring bearing against the sides of the bore; whereby the median of the thrust is applied to the disk substantially to one side of its center, thereby causing the disk to rotate with respect to the handle when the disk is pushed along a surface to be abraded.

3. A hand sander including a disk with an abrasive face, a pintle on the disk, an expansible spring positioned in a circumferential groove near the outer end of the pintle, a handle having a top surface adapted to receive a thrust from a hand, and a boss on the handle bored to receive and retain the pintle, the boss being positioned to one side of the handle, whereby the median of a thrust exerted upon the handle is applied substantially away from the center of the disk, thereby causing the disk to rotate with respect to the handle when the disk is pushed along a surface to be abraded.

CHARLES W. WERNTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 550,099 Detrick Nov. 19, 1895 1,653,108 Koenig Dec. 20, 1927 1,741,145 Drennon Dec. 31, 1929 2,008,260 Reineman July 16, 1935 2,116,491 Mall May 3, 1938 

